Alkali Silica Reaction in Concrete Using a New Portland Cement Made from Municipal Waste Incinerator Ash

研究结果表明：(1)含碎瓶玻璃集料的砂浆中测得的碱-硅酸反应膨胀量远大于含PYREX玻璃集料的砂浆中测得的膨胀量。(2)与瓶装玻璃粉相比，氧化锂玻璃粉对碱-硅酸反应的抑制效果显著。掺入氧化锂玻璃微粉可显著降低ASR的膨胀，这主要是由于玻璃微粉作为火山灰的性质和玻璃中锂的析出所致。(3)即使在高碱水泥砂浆中掺入高达20%的飞灰，也完全抑制了ASR的膨胀。(4)纵向约束下产生的膨胀压力与自由膨胀成正比，但Na2Oe高达2.0和2.5%的15%煅烧火石砂浆表现出高膨胀，但膨胀压力低。富碱砂浆的这种异常行为似乎是由于富碱ASR凝胶的产生。(5)膨胀试验中获得的结果表明，即使含有高碱含量的ASR凝胶的混凝土在实验室膨胀试验中表现出很大的膨胀，在受约束的混凝土构件中，由膨胀压力引起的二次应力造成的损害可能不是很大。(6)锂离子对具有活性集料的砂浆的侵入可以阻止砂浆在0.5N LiOH溶液中浸泡后不久的膨胀。(7)在长期密封在乙烯基袋中预养护的砂浆中，砂浆的膨胀早些时候就开始减少。(8)在水泥浆体和活性集料颗粒之间不远处的大多数ASR凝胶中的碱似乎被外部溶液提供的锂离子所取代

The results obtained in this study are as follows ;(1)Measured expansions due to the alkali silica reaction in mortars containing a crushed bottle glass aggregate were far greater than in mortars made with the Pyrex glass aggregate.(2)The lithia glass powder was conspicuously effective in the suppression of the alkali silica reaction as compared with the bottle glass powder. Great reduction in expansion with the addition of the lithia glass powder appear to be derived from the nature of the glass powder as a pozzolan and the lithium released from the glass.(3)The addition of as much as 20% fly ash completely suppressed ASR expansion even in high alkali cement mortars with the crushed bottle glass aggregate.(4)The expansive pressure generated under longitudinal restraint was in proportion to free expansion except that the 15% calcined flint-containing mortars with a high Na2Oe of 2.0 and 2.5% showed high expansions, but low expansive pressures. This exceptional behavior of the alkali-rich mortars appears to be due to the production of alkali-rich ASR gels.(5)The results obtained in the expansive pressure experiment suggest that, even if concretes containing ASR gels with a high alkali content exhibit great expansions in laboratory expansion tests, damages due to secondary stresses induced by the expansive pressure in concrete members under restraint may not be significant.(6)The intrusion of lithium ions into mortar with a reactive aggregate could arrest the expansion of mortars shortly after immersion in 0.5 N LiOH solution.(7)Expansion of mortars started decreasing earlier in mortars pre-cured in sealed in vinyl sacks for longer periods.(8)The alkalis in most ASR gels not far from interfaces between the cement paste and reactive aggregate particles appear to be replaced by the lithium ions supplied from the external solution